Wednesday, June 3, 2015

EAST MOXIE TOWNSHIP, Maine—Lee Kantar crouches over a dead moose calf and pulls a clump of hair from its straggly shoulder.

A few days earlier, the sickly ten-month-old animal had waded through deep snow to this sun-dappled stand of spruce trees in western Maine, laid down, and died.

"See how white those hairs are?" says Kantar, a moose biologist for the state.

It's a telltale sign that the calf was becoming a "ghost moose"—an animal so irritated by ticks that it rubs off most of its dark brown hair, exposing its pale undercoat and bare skin.

With their skinny necks, emaciated bodies, and big, hairless splotches, these moose look like the walking dead as they stumble through the forest.

And in recent years in New England, ghost moose sightings have become increasingly familiar.

The reason is likely climate change, biologists say, which is ushering in shorter, warmer winters that are boosting the fortunes of winter ticks. The tiny creatures latch on to moose here in staggering numbers: One moose can house 75,000 ticks, which are helping to drive a troubling rise in moose deaths, especially among calves. (See "New Climate Change Report Warns of Dire Consequences.")

Mostly wiped out in New England by hunting in the 1800s, moose populations had begun rebounding in the late 1970s, thanks to a suddenly abundant food source—new spruce-fir forests that took root following a pest outbreak that wiped out much of the former forest.

By the late 1990s, about 7,500 moose were living in New Hampshire. But in 2013, the population there had dropped to 4,500. In vastly bigger Maine, which has about 60,000 moose—the densest population in the lower 48 states—there's a suspected decline, but there's less data.

It's unlikely that these leggy deer will disappear entirely from New England, but the surge in moose deaths has made investigating the causes a top priority for the region's scientists.

Though winter tick is the main culprit, scientists are trying to unravel the bigger mystery of what else is contributing to the deaths. Moose are highly susceptible to several kinds of parasites, and it's likely that many factors are at play.